Megalneusaurus
Encyclopedia
Megalneusaurus is an extinct genus
of large pliosaur
that lived in the Sundance Sea
during the Kimmeridgian
, ~156-152 million years ago, in the Late Jurassic
.
The genus and type species
was based upon ribs, vertebrae, a fore-paddle and fragments of the pectoral girdle discovered in Wyoming
, USA in 1895. The species named as Megalneusaurus rex (meaning "great swimming lizard King") in 1898.
However some of this material has since been lost, although new material has been discovered from the same site.
Based upon the bones very large size, it appears to have grown to a size comparable to Liopleurodon
.
Material from southern Alaska have been referred to Megalneusaurus, although this material is from an individual of much smaller size.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of large pliosaur
Pliosaur
Pliosauroidea is an extinct clade of marine reptiles. Pliosauroids, also commonly known as pliosaurs, are known from the Jurassic and Cretaceous Periods. The pliosauroids were short-necked plesiosaurs with large heads and massive toothed jaws. These swimming reptiles were not dinosaurs but distant...
that lived in the Sundance Sea
Sundance Sea
The Sundance Sea was an epeiric sea that existed in North America during the mid to late Jurassic Period of the Mesozoic Era. It was an arm of what is now the Arctic Ocean, and extended through what is now western Canada into the central western United States...
during the Kimmeridgian
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma . The Kimmeridgian follows the Oxfordian and precedes the Tithonian....
, ~156-152 million years ago, in the Late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
.
The genus and type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
was based upon ribs, vertebrae, a fore-paddle and fragments of the pectoral girdle discovered in Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
, USA in 1895. The species named as Megalneusaurus rex (meaning "great swimming lizard King") in 1898.
However some of this material has since been lost, although new material has been discovered from the same site.
Based upon the bones very large size, it appears to have grown to a size comparable to Liopleurodon
Liopleurodon
Liopleurodon is a genus of large, carnivorous marine reptile belonging to the Pliosauroidea, a clade of short-necked plesiosaurs. Two species of Liopleurodon lived during the Callovian stage of the Middle Jurassic Period , while the third, L. rossicus, lived during the Late Jurassic...
.
Material from southern Alaska have been referred to Megalneusaurus, although this material is from an individual of much smaller size.